March 23, 2009 04:31 AM AKDT

This explosion was very intense, with plume heights up to 18.3 km. Electrical activity
occurred for 53.4 minutes. The first discharges from this explosion were discrete, and located
over the volcano. After about 1.5-2 minutes of low frequency discrete activity, the lightning
transitions to an intense phase of mostly amorphous activity. Overall, this structureless
activity was not localized to the vent alone. It also occurred to the north of the volcano in
an area of at least 5 km in radius. Just like the prior explosions, the lightning
becomes more structured and discrete over time.